Table 2.
Confirmatory factor analysis fit indices and model-based omega coefficients
| Index | TAS-20 Bifactor: SPARK | TAS-20 Bifactor: HPP | 11-item Bifactor: SPARK | 11-item Bifactor: HPP |
|---|---|---|---|---|
| Model FIT INDICEs | ||||
| χ2 (df)a | 590.6 (145) | 669.9 (145) | 151.6 (33) | 124.0 (33) |
| CFIcML | 0.924 | 0.900 | 0.970 | 0.978 |
| TLIcML | 0.900 | 0.869 | 0.951 | 0.963 |
| RMSEAcML [90% CI] | 0.072 [0.066, 0.078] | 0.086 [0.081, 0.092] | 0.080 [0.069, 0.092] | 0.068 [0.056, 0.079] |
| SRMRu [90% CI] | 0.036 [0.033, 0.004] | 0.051 [0.047, 0.056] | 0.020 [0.017, 0.024] | 0.019 [00.015, 0.023] |
| WRMR | 1.119 | 1.565 | 0.768 | 0.699 |
| |Residuals| > 0.1 | 2.60% | 8.90% | 0% | 0% |
| Largest residual | 0.149 | 0.225 | 0.084 | 0.055 |
| Bifactor coefficients | ||||
| ωT/ωH | 0.912/0.773 | 0.914/0.741 | 0.929/0.861 | 0.925/0.952 |
| ωS/ωHS (DIF) | 0.906/0.162 | 0.880/0.224 | 0.913/0.087 | 0.892/0.071 |
| ωS/ωHS (DDF) | 0.854/0.145 | 0.803/0.120 | 0.800/0.163 | 0.839/0.223 |
| ωS/ωHS (EOT) | 0.451/0.300 | 0.512/0.307 | – | – |
| ωS/ωHS (REV) | 0.559/0.441 | 0.692/0.689 | – | – |
Fit indices that above the a priori cutoffs for acceptable model fit (CFI/TLI > 0.95, RMSEA < 0.06, SRMR < 0.08, WRMR < 1, all residuals < 0.1) are presented in bold. TAS = Toronto Alexithymia Scale; SPARK = Simons Powering Autism Research Knowledge; HPP = Human Penguin Project; CFIcML = comparative fit index (categorical maximum likelihood estimation); TLIcML = Tucker–Lewis Index (categorical maximum likelihood estimation); RMSEAcML = root mean square error of approximation (categorical maximum likelihood estimation); SRMRu = population-unbiased standardized root mean square residual; WRMR = weighted root mean square residual; ωT = omega total (composite reliability of total score); ωH = omega hierarchical (proportion of total score variance accounted for by general factor); ωS = omega subscale (composite reliability of subscale score); ωHS = omega hierarchical subscale (proportion of subscale score variance accounted for by specific factor); DIF = difficulty identifying feelings; DDF = difficulty describing feelings; EOT = externally oriented thinking; REV = reverse-coded item method factor
aAll p values < 0.001